Manufacture of blades



D. J. CLARKE MANUFACTURE OF BLADES Aug. 9, 1960 2 Sheets-Sheet 1 FiledApril 25, 1958 mw-zurox I DANIEL J. CLARKE I ATIORN EY S 1950 -D. J.CLARKE 2,948,197

MANUFACTURE OF BLADES Filed April 25, 1958v 2 Sheets-Sheet 2 I FIG-6FIG-5 INVENTOR.

DANIEL J. CLARKE ATTORNEYS Patented Aug. 9, 1950 MANUFACTURE OF BLADESFiled Apr. 25, 1958, Ser. No. 731,003 8 Claims. gel. 90-A-s9 Thisinvention relates to work supports and more particularly to an apparatusfor supporting blade blanks in forming blades for turbines, compressorsand the like.

it is frequently required in the formation of such hollow blades toprovide an external nose radius less than the thickness of the sheetmaterial which is folded about the leading edge. The folding may beaccomplished if the nose is grooved internally before folding. Thegroove is proportioned so that its sides come close together when theopposite walls are brought together into blade relation by the foldingoperation. This proximity of the sides of the groove facilitates thefilling of the groove by and bonding its sides together by solder. Sincethe walls are thin, for instance from 0.020 in. to 0.050 in.,

' the cutting of the groove is diflicult to accomplish.

It is a principal object of this invention to provide an apparatus forholding'a blade blank in fixed position,

free of distorting forces, during grooving of the inner nose wall.

Another object of this invention is to provide an apparatus having aremovablemandrel for accurately locating the nose of a blade blank inoperating position and having supporting structure for holding the bladein that position after the mandrel is removed and during grooving of theinner nose wall. l

Referring to the drawings which disclose a preferred embodiment of theinvention: I

Fig. 1 shows in perspective a contoured blade blank which is to befolded about a small radius at the nose;

Fig. 2 is an end view of an enlarged fragment of the blank in Fig. 1;

Fig. 3 is a perspective view of a holding fixture, partly in section,wherein the mandrel is in position to move entire length of the nose.

are also mounted on the upper surface of base plate 15. The bearingelements 20 are spaced apart to expose a portion of the upper surface ofthe back-up plate 16 along the length thereof and further, are shaped toconform to the shape of the outer surfaces of side walls 12, so thatwhen the blade blank 10 is placed in the apparatus a substantial area ofthe walls 12 will be in contact with the elements 20 to reduce thepossibility of distortion occurring during grooving. The elements 20 arepreferably made of an elastomeric material-such as Devcon, which is aplastic metal consisting of approximately 80% fine steel powders and 20%of an extremely strong plastic and is manufactured by the ChemicalDevelopment Corporation of Danvers, Mass. Such material is initiallyplastic and can be molded to the exact shape of the blade walls, andthen permitted to harden into the final, desired shape.

A pair of hold-downs 25 having generally horizontal upperwalls 26,vertical end walls 27 and vertical pressure transmitting walls 28, areconnected to the upper edges of support Walls 17' by means of the pins30 which fit through appropriately formed holes in walls 26. Eachpressure transmitting wall 28 extends downwardly into the interior ofblade blank 10 and carries a shoe 31 which is constructed of the samematerial as bearing elements 20, the shoes having bearing surfaces 32conforming to the shapes of the inner surfaces of side walls 12 oppositebearing elements 20.

When a blank is to begrooved, it is placed nose down in the apparatus sothat the outer surface of its leading edge, L.E., contacts back-up plate16 throughout the However, due to the fact that the shape of individualblade blanks may vary, it is possible that the leading edge of a blankwill occasionally fail to make proper contact with the back-up plate.Therefore, a removable mandrel 35 has been provided which is insertableinto the spacebetween pressure transmitting walls 28 with its lower edgebearing on the inside surface of the nose wall. It can be forced downagainst the nose wall by releasable means comprising a bar 36 mandrel35' to force the leading edge against the surface the nose of the bladeblank intoan operating position for cutting of the nose groove; 7

Fig. 4 shows the fixture means supported below a cutter for cutting thegroove in'the nose of the blank, the mandrel being removed;

Fig. 5 is an enlarged end view of a portion of the nose with the groovetherein; and

Fig. 6 is an end view of a blade made from the grooved blank.

Referring now to the drawings, Fig. 1 shows a blade blank 10, such. aswould beheld by the present apparatus, whose nose portion 11 andopposite side wall portions 12 have been formed to their.selectedcontours. ...The walls define an open side and the leading edgeLE. at the nose of the blank. The nose is to be folded about the leadingedge to provide an external radius of the nose equal to or less than thethickness of the wall at the nose. Fig. 2 is an enlarged view of afragmentary section showing the relatively large nose curvature prior tothe folding operation.

The apparatus is shown in Fig. 3 and comprises a base including thegenerally rectangular base plate 15 and an elongated back-up plate 16which is attached to the upper surface of plate 15. Support means madeup of upstanding walls 17 and opposed bearing elements 20 of back-upplate 16; After the mandrel has been forced downwardly, the hold-downs25 are tightened to urge the shoes 31 into engagement with the innerside Wall portions of the blade blank. This is done by means of toggleclamps 50 bearing on the steps 51 of the holddowns. Two such clamps areused at each end of the hold-downs.

Once the hold-downs have been tightened into position the. handle 45isbac ked away from bar 36 and the bar pivoted out of the way so thatmandrel 35 can be removed. Since the hold-downs maintain the noseportion of the blade in proper position for grooving, the removal of themandrel does not in any way affect the position of the blade. The entireapparatus can then be properly positioned beneath a cutting member, suchas the rotating blade 52 shown in Fig. 4 and the inner nose wallgrooved.

Fig. 5 shows the nose of the blade blank enlarged to portray clearly thegroove 55 which has been cut in the nose wall. Fig. 6 shows the blademade by folding the blade blank at the leading edge about the desiredsmall radius and after rounding off the trailing edge, the groove 55having been filled with brazing material 56.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that this inventionis not limited to this precise form of apparatus and that changes may bemade therein without departing from the scope of the invention which isdefined in the appended claims.

What is claimed is:

A 1. In combination in an apparatus for supporting a hollow blade blankfor internally grooving the nose wall thereof comprising a supportingfixture, a back-up plate mounted on said fixture, contoured bearingmeans fixed on said fixture for bearing against each of the contouredwalls of a blade blank externally thereof, a removable mandrelpositioned between said walls, releasable means for pressing saidmandrel against the inner surface of said nose wall to bottom said noseagainst said plate in accurate relation thereto and throughout thelength thereof, releasable hold-downs operable to press said wallsagainst their respective bearing means with said nose wall supported onsaid back-up plate and accessible internally to a grooving tool while sosupported.

2. An apparatus according to claim 1 wherein the bearing means comprisesa plastic-like material casting.

3. An apparatus according to claim 1 wherein the hold-downs have shoesfor pressing the walls of said blade blank against said bearing means,said shoes being made of a plastic like material.

4. In combination in an apparatus for supporting a hollow blade blankfor internally grooving the nose wall thereof comprising a supportingfixture, a back-up plate mounted on said fixture, contoured bearingmeans fixed on said fixture for hearing against each of the contouredwalls of a blade blank externally thereof, a removable mandrelpositioned between said walls, releasable means for pressing saidmandrel against the inner surface of said nose wall to bottom said noseagainst said plate in accurate relation thereto throughout the lengththereof, releasable hold-downs operable to press said walls againsttheir respective bearing means, and means retaining said hold-downs inoperative position for securing said Walls after said mandrel is removedfrom said nose wall.

5. An apparatus for supporting a blade blank having nose and side wallportions in fixed position for grooving of the inner nose wall,comprising a base, support means mounted on said base and includingbearing elements for contact with the outer surfaces of said side wallportions, means including a removable mandrel for locating said noseportion in operating position with substantially the entire length ofthe outer surface of said nose against said base, hold down means spacedfrom each side of said removable mandrel and engageable with the innersurfaces of said side wall portions to hold said blade blank inposition, and means engageable with said hold down means for maintainingsaid hold down means in contact with the inner surfaces of said sidewall portions to hold said inner nose wall in position for groovingfollowing removal of said mandrel.

6. An apparatus for supporting a blade blank having nose and contouredside wall portions in fixed position for grooving of the inner nosewall, comprising a base having a back-up plate mounted on the uppersurface thereof, support means mounted on said base and includingbearing elements conforming to the shapes of said side walls, saidbearing elements being spaced apart and exposing a portion of the uppersurface of said back-up plate along the length thereof, a removablemandrel movable into an operating position to press said nose portioninto contact along substantially the entire length of the leading edgewith said back-up plate, hold down means spaced from each side of saidremovable mandrel and engageable with the inner surface of said sidewalls to hold said blade blank in position after said mandrel isremoved, and means engageable with said hold down means for maintainingsaid hold down means in contact with the inner surfaces of said sidewalls to hold said inner nose wall in position for grooving.

7. An apparatus for supporting a blade blank having nose and side wallportions in fixed position for grooving of the inner nose Wall,comprising a base having a back-up plate mounted on the. upper surfacethereof, support means mounted on said base and including hearingelements conforming to the shapes of portions of the outer surfaces ofsaid side Walls, said bearing elements being spaced apart and exposing aportion of the upper surface of said back-up plate along the lengththereof, a removable mandrel insertable into the space between saidbearing elements for contact with the inner nose wall of said blank,means including a pivotally mounted bar for exerting a downward forceagainst said mandrel to force said blade nose portion into contact alongsubstantially the entire length of its leading edge with said back-upplate, hold down means connected to said support means, said hold meansincluding pressure transmitting walls spaced from each side of saidmandrel and extending into the nose portion of said blade blank, shoescarried on said pressure transmitting walls and having bearing surfacesfor contact with the inner surfaces of said side walls, and clamp meansengageable with said hold down means for maintaining said shoes incontact with the inner surfaces of said side walls.

8. An apparatus for supporting a blade blank having nose and side wallportions in fixed position for grooving of the inner nose wall,comprising a base having a backup plate mounted on the upper surfacethereof, support means mounted on said base and including bearingelements conforming to the shapes of portions of the outer surfaces ofsaid side walls, said bearing elements being spaced apart and exposing aportion of the upper surface of said back-up plate along the lengththereof, a removable mandrel insertable into the space between saidbearing elements for contact with the inner nose wall of said blank,means including a pivotally mounted bar for exerting a downward forceagainst said mandrel to force said blade nose portion into contact alongsubstantially the entire length of its leading edge with said back-upplate, hold down means connected to said support means, said hold meansincluding pressure transmitting walls spaced from each side .of saidmandrel and extending into the nose portion of said blade blank, shoescarried on said pressure transmitting walls and having bearing surfacesfor contact with the inner surfaces of said side walls, and clamp meansengageable with said hold down means for maintaining said shoes incontact with the inner surfaces of said side walls.

Weber Dec. 27, 1955 Dougherty Mar. 11, 1958 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No. 2,948,197 August 9, 1960;

Daniel J. Clarke It is hereby certified that error appears in theprinted specification of the above numbered patent requiring correctionand that the said Letters i Patent should read as corrected below.

Column 3, line '15, strike out "and" and insert same, after "of," inline 16, same column.

Signed and sealed this 31st day of January 1961.

SEA L) Attest:

KARL H. AXLINE ROBERT C. WATSON v l Attesting Officer Commissioner ofPatents

